This data package contains reflectance data and associated aerial images collected using a helicopter-suspended "albedo box," in which a shortwave radiometer and camera where mounted facing downward. The purpose of this study was to measure how surface reflectance varies within and across landscape types (glaciers, lakes, and soils) over the course of a single field season as well as across multiple field seasons. We made five flights in the 2015-2016 field season (20 November 2015, 7 December 2015, 24 December 2015, 5 January 2016, and 12 January 2016), five flights in the 2016-2017 field season (11 November 2016, 3 December 2016, 14 December 2016, 3 January 2017, 23 January 2017), four flights in the 2017-2018 field season (22 November 2017, 7 December 2017, 27 December 2017, 13 January 2018), and two flights in the 2018-2019 field season (23 November 2018, 9 January 2019). Flights originated from Lake Hoare field camp, flew down-valley over Canada Glacier, Lake Fryxell, and Commonwealth Glacier, then turned around and flew up-valley to Taylor Glacier Meteorological Station, after which they returned to Lake Hoare field camp. Flights took roughly one hour and were flown at approximately 25.72 m s-1 (50 knots) and 91.44 m (300 ft) above the ground surface. These data can be normalized to incoming solar radiation (measured in-situ at meteorological stations) to calculate landscape albedo. When collected several times throughout a season, these results can show how snow distribution and physical changes to glacier and lake ice impact the amount of incoming radiation that is absorbed, while also tracking the influence of deposited sediment on ice surfaces. Moreover, these data are important for quantifying the long-term changes in energy connectivity between the atmosphere and the landscape (i.e., addressing Hypothesis 1 of the MCM V funding cycle).
Data were collected by helicopter using instruments mounted to a weighted box with a fin to reduce swing in-flight (i.e., an "albedo box"). A shortwave radiometer (CMP3, Kipp and Zonen) was mounted to point down at the valley floor. Additionally, a downward facing camera (CC5MPX, Campbell Scientific) was mounted next to the radiometer. A GPS unit (GPS16X-HVS, manufactured by Garmin for Campbell Scientific) was fixed to the top of the box. All instruments were wired in to a data logger (CR1000, Campbell Scientific) and programmed to collect data every three seconds. Before each flight, the radiometer and camera lens were cleaned. The albedo box was attached to a helicopter with a 6.1 m (20 ft) lead line. Data were downloaded and archived after each flight. Due to a hardware failure, images captured during the two 2018-2019 season flights were not recorded, and therefore these images are not included in the data package. Flights spanned the entire Taylor Valley and were routed over glaciers originating from the Asgard Range, the major lakes, and Taylor Glacier. Pilots were instructed to fly at 91.44 m (300 ft) off the ground and at a speed of 25.72 m s-1 (50 knots). Flights occurred on completely cloud free days or homogeneously cloudy days ensure there was no variability in incoming radiation across the Valley.